#include<bits/stdc++.h>
using namespace std;
const int N = 1e5+5;
int a[N];
int n;
int check(int a){
	for(int i = 2;i <= a; i ++){
		if(i % 2 == 0 || i % 3 == 0 || i % 5 == 0 || i % 7 == 0) continue;
		if(a % i == 0) return 0;
	}
	return 1;
}
int main()
{
	a[1]=1;
	cin >> n;
	int t = 2;
	int i = 2;
	while(t <= n+1){
		if(check(i) == 1){
			a[t++] = i;
		}
		i++;
	}
	cout<<a[n];
}